Oh, and one more thing: Nautilus Elementary got (about 2-3 days ago) a really nice combined mode button (only works with the horizontal toolbar):

If you want to remove Nautilus Elementary 2.30 and return to the default Nautilus in Ubuntu 10.04 Lucid Lynx, I suggest you use PPA Purge, a very easy to use utility which completely removes and applications installed from a PPA and installs the packages in the official Ubuntu repositories.

Update: you can now get Nautilus Elementary Breadcrumbs for any theme. Read here how to do it.